1. Field Of The Invention
The invention relates to evaluation of and/or design of CO.sub.2 flooding processes for enhanced oil recovery.
2. Description Of The Prior Art
A great need exists to recover additional hydrocarbons from subterranean formations after primary production is no longer economical. Recovery processes involving mobilizing and moving hydrocarbons through a hydrocarbon bearing subterranean formation from an injection well to a production well by injecting a mobilizing fluid into the injection well are well known. One example of such a mobilizing fluid is a fluid comprising CO.sub.2.
One of the factors inhibiting more rapid development of such enhanced recovery methods is the tailoring of a process to a reservoir. Hydrocarbon bearing reservoirs are each unique and can respond in many unexpected and unpredictable ways to such enhanced recovery processes.
At present, the general practice is to use all of the knowledge available including laboratory data and reservoir properties to design a best evaluation of what will technically be feasible and cost effective in the reservoir, and then to conduct a pilot test project for each reservoir to prove out or redesign the flood process. These pilot projects, however, are very protracted sometimes taking several years to conduct, and run into costs of many millions of dollars.
It has also been suggested that such enhanced oil recovery projects can be designed and/or evaluated by various single well tests. Examples of such tests are shown in U.S. Pat. No. 4,099,565 to Sheely, Jr., et al. and U.S. Pat. No. 4,168,746 to Sheely, both assigned to the assignee of the present invention.